Came out of code review for JDK-8292678:

We should remove the root .classpath as there are no sources in the root Eclipse project.
It could be confusing for a non-Java project to have files associated with a Java project. Also, we want to minimize the amount of unneeded files (if Gradle knew how to generate these itself we wouldn't need to check them in). Since we are doing a cleanup, it is the right place to do it.

Verify that there is no impact on:
- importing a freshly checked out repo as a gradle project into Eclipse

Also, perhaps, we should fix the project name rt -> jfx in the .project file.
Also, add hs_err*, .DS_Store to .gitignore